1. Field of the Invention
The present invention relates to an air conditioner for a vehicle that is used to conduct heating and cooling for front and rear seats inside the vehicle, and more particularly, to a multi-zone type air conditioner for a vehicle that enables a rapid temperature control, and can independently control the temperature of front and rear areas and left and right areas inside the vehicle.
2. Background of the Related Art
Typically, a vehicle is provided with an air conditioner that heats or cools internal and external air to supply or circulate the heated or cooled air to the interior thereof, thereby keeping the air inside the vehicle at an appropriate temperature and making occupants inside the vehicle feel good. The air conditioner generally includes a casing in which a plurality of air flow passages are formed therein, a blower disposed at one side of the casing for absorbing the internal and external air in/from the vehicle to blow the air to the casing, an evaporator for making the internal and external air flowing therein cool, and a heater core for heating the internal and external air.
Such the air conditioner for a vehicle is provided with a cooling device that is constructed such that refrigerants, which are compressed by means of a compressor that is driven by power of an engine, which are passed through a condenser, an expansion valve and the evaporator, and which flow into the compressor again, are heat-exchanged with the internal and external air by the blower to keep the air in the interior of the vehicle cool, and with a heating device that is constructed such that the cooling water, which is used to keep the engine cool, which is passed through the heater core, and which is returned to the engine, is heat-exchanged with the internal and external air flowing out by the blower to keep the air in the interior of the vehicle heated.
In the conventional air conditioner for the vehicle, however, vent outlets and floor outlets that supply the air from the air conditioner to the interior of the vehicle are disposed on the front sides of the front seats, which makes the cooling and heating efficiencies for the rear seats substantially low.
To solve the above-mentioned problems, there is provided Korean Publication No. 2001-0059264 that is filed by the same applicant as the present invention, in which a main air conditioner is provided with an auxiliary air conditioning unit that is operated independently of the main air conditioner in order to efficiently achieve the cooling and heating for the rear seats.
FIG. 1 is a schematic view of showing a conventional air conditioner for a vehicle, and FIG. 2 is a sectional view of showing an auxiliary air conditioner used for the conventional air conditioner for the vehicle. The main air conditioner Ma blows air through wind shield openings 292′a and 292′b, center and side openings 291′a and 291′b, and floor openings 293′a and 293′b, and the auxiliary air conditioner Aa blows air through vent outlets 9a and 9b and floor outlets 10a and 10b. 
According to the prior art, the auxiliary air conditioner Aa is separately mounted from the main air conditioner Ma on a console space portion for the vehicle, in order to efficiently execute the cooling and heating for the rear seats. The auxiliary air conditioner Aa includes an evaporator and a heater core, having working fluids like refrigerants that branched from the main air conditioner and flow into the interior thereof to execute the heat exchange with the internal and external air. At this time, the supply of the working fluid is controlled by means of a solenoid valve or a water valve such that the temperature of the air from the air conditioner can be adjusted.
According to the prior art, however, the control of temperature of the air from the air conditioner is made by permitting or stopping the supply of the working fluids such that because of the continuously flowing characteristic of the fluid the temperature of air from the air conditioner is not rapidly changed in response to the manipulation of a user, thereby inevitably causing the delay of time for the temperature change. For instance, in a case where cooling is needed in the process of heating, the temperature change is not made rapidly because of the cooling water remaining in the heater core, and therefore, a predetermined period of time elapses before the cool air flows out.
To solve the above-mentioned problems, thus, it is possible to mount an auxiliary air conditioning unit on the left and right sides of the rear portion of the vehicle, respectively, for executing the temperature control independently of each other, but in this case, the evaporator and the heater core are separated to the left and right sides, such that it is necessary to form a plurality of flow passages through which the refrigerants and cooling water flow in and out that are connected from the main air conditioner positioned at the front of the vehicle to the auxiliary air conditioning units positioned at the rear thereof. This causes the whole installation space of the air conditioner to be bulky and makes the number of working processes and the manufacturing cost due to the increase of the number of parts substantially raised.